近48年河北平原夏玉米季花期高温时空分布特征

Temporal and Spatial Distribution Characteristics of High Temperature in Flowering Season of Summer Maize in Hebei Plain in Recent 48 Years

选择河北省86个县(市、区)1971年~2018年6~9月份气象数据,对生育期平均气温与32℃~40℃高温日数变化特征、花期(8月5~25日)≥32℃和≥34℃累计度日(EDD)及高温发生天数(EHD)时空变化特征进行分析,明确河北省夏玉米季气温变化和花期高温的时空分布特征。结果表明,1971~2018年夏玉米季,阶段平均气温上升趋势明显,倾向率0.29℃/10年;全区≥32℃、≥34℃、≥37℃和≥40℃共4个高温累计日数开始呈上升趋势,倾向率分别为4.04 d/10年、2.36 d/10年、0.6 d/10年和0.08 d/10年。夏玉米花期高温有加剧趋势,2011~2018年情况最为明显,花期≥32℃、≥34℃年均累计日数和有效积温从70年代至今有增多趋势,东部低平原区出现高温概率高于西部。

In order to clarify the temporal and spatial distribution characteristics of temperature change and flowering high temperature in summer maize season in Hebei province,based on the meteorological data of 86 coun⁃ties(cities and districts)in Hebei province from 1971 to June to September 2018,the temporal and spatial variation characteristics of average temperature and high temperature days at 32℃-40℃,cumulative degree days(EDD)at≥32℃and≥34℃and high temperature occurrence days(EHD)during florescence(August 5-25)were analyzed.The results showed that the average temperature in summer maize season from 1971 to 2018 has an obvious upward trend,tendency rate:0.29℃/10 a.The cumulative number of high temperature days≥32℃,≥34℃,≥37℃and≥40℃in the whole region began to show an upward trend,and the tendency rates were 4.04 d/10 a,2.36 d/10 a,0.6 d/10 a and 0.08 d/10 a,respectively.The high temperature of summer maize tends to intensify during flowering,which is the most obvious from 2011 to 2018.The average annual cumulative days and effective accumulated temperature at flowering≥32℃and≥34℃had increased since the 1970s.The probability of high temperature in the eastern low plain was higher than that in the west.